U.S. patent number 6,305,468 [Application Number 09/322,099] was granted by the patent office on 2001-10-23 for downhole screen and method of manufacture.
This patent grant is currently assigned to Baker Hughes Incorporated. Invention is credited to John T. Broome, Gary Corbett, Jim Goodson, Elmer R. Peterson, Benn A. Voll, Yusheng Yuan.
United States Patent |
6,305,468 |
Broome , et al. |
October 23, 2001 |
Downhole screen and method of manufacture
Abstract
A method and apparatus for manufacturing any given length of a
completion filter assembly is described. An outer perforated jacket
is assembled over the filter media, which is itself placed over a
coarse support screen or drainage layer. In the preferred
embodiment, the drainage layer and outer jacket have end rings such
that when advanced through a die are pushed together with the
filter media in between to effect a seal of the subassembly. The
subassembly can then be placed on a support pipe which is
perforated, and if metallic, the end rings are welded to the
support pipe to complete the assembly. Optionally, many of the
components can be made of materials which lend buoyancy to the
assembly so that when it is advanced into a long lateral, it will
float to assist in its proper positioning.
Inventors: |
Broome; John T. (The Woodlands,
TX), Voll; Benn A. (Houston, TX), Corbett; Gary
(Aberdeen, GB), Goodson; Jim (Porter, TX), Yuan;
Yusheng (Houston, TX), Peterson; Elmer R. (Lafayette,
LA) |
Assignee: |
Baker Hughes Incorporated
(Houston, TX)
|
Family
ID: |
23253413 |
Appl.
No.: |
09/322,099 |
Filed: |
May 28, 1999 |
Current U.S.
Class: |
166/233; 166/230;
210/499; 29/896.62 |
Current CPC
Class: |
E21B
43/08 (20130101); Y10T 29/49604 (20150115) |
Current International
Class: |
E21B
43/08 (20060101); E21B 43/02 (20060101); E03B
003/22 () |
Field of
Search: |
;166/230,232,233,228
;210/497.1,499 ;29/896.61,896.62 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
0 186 317 A1 |
|
Jul 1986 |
|
EP |
|
2277947A |
|
Nov 1994 |
|
GB |
|
1534184 A1 |
|
Jan 1990 |
|
RU |
|
Other References
Houston Well Screen Company brochure, "Endrua-Pak", 9 pages, (date
unknown).* .
3M Ceramic Fiber Products brochure, "3M Nextel Ceramic Fabric
Offers Space Age Protection", 4 pages, 1997..
|
Primary Examiner: Neuder; William
Assistant Examiner: Walker; Zakiya
Attorney, Agent or Firm: Rosenblatt; Steve
Claims
What is claimed is:
1. A downhole filter assembly, comprising:
at least two filtering layers having a tubular shape and mounted
one over the other and secured to each other without welding;
said layers comprise and inner and an outer layer;
said inner layer is trapped by virtue of mechanically deforming
said outer layer against it;
a perforated base pipe extending through said layers, said layers
having ends extending beyond the perforations in said base pipe and
fixedly secured to said base pipe.
2. The assembly of claim 1, wherein:
said layers are joined to each other by deformation resulting from
an applied force.
3. The assembly of claim 2, wherein:
one of said layers is formed from a sheet rolled into a tubular
shape with ends overlapping by less than about 10.degree..
4. The assembly of claim 2, wherein:
at least one of said layers further comprises end rings, said
layers secured at said end rings by a mechanical deformation.
5. The assembly of claim 4, wherein:
said end rings are nonremovably attached to said base pipe to seal
the ends of said layers.
6. The assembly of claim 2, further comprising:
a third layer mounted over said two layers wherein, going outwardly
from said base pipe, said layers comprise a coarse filter, a fine
filter and a perforated protective jacket, and wherein all of said
layers are secured to each other on their ends without welding.
7. The assembly of claim 6, wherein:
said filter layers and said protective jacket are secured on said
ends by deformation resulting from an applied force.
8. The assembly of claim 7, wherein:
said protective jacket comprises inwardly directed protrusions in
contact with said fine filter at spaced locations over its length
between said end portions which are secured to said fine
filter.
9. The assembly of claim 7, wherein:
said assembly of said coarse and fine filters and said protective
jacket are nonremovably attached on said ends to said base
pipe.
10. The assembly of claim 6, wherein:
said fine filter comprises of a sheet of screen material rolled
into a tubular shape with ends overlapping by less than about
10.degree..
11. The assembly of claim 6, wherein:
said protective jacket contacts said fine filter between said ends
and said filter assembly can resist internal burst pressure of over
about 1000 psig.
12. A downhole filter assembly, comprising:
at least two filtering layers having a tubular shape and mounted
one over the other and secured to each other without welding;
a perforated base pipe extending through said layers, said layers
having ends extending beyond the perforations in said base pipe and
fixedly secured to said base pipe;
said layers are joined to each other by deformation resulting from
an applied force;
a third layer mounted over said two layers wherein, going outwardly
from said base pipe, said layers comprise a coarse filter, a fine
filter and a perforated protective jacket, and wherein all of said
layers are secured to each other on their ends without welding;
said fine filter comprises of a sheet of screen material rolled
into a tubular shape with ends overlapping by less than about
10.degree.;
said protective jacket and said coarse filter comprise end rings
with said fine filter extending in between;
said fine filter being squeezed between said rings on both ends to
hold the assembly of said filter and protective jacket
together.
13. The assembly of claim 12, wherein:
said protective jacket comprising projections oriented toward said
fine filter which are in contact, at spaced locations, with said
fine filter between said end rings.
14. A method of running in a screen for downhole use,
comprising:
assembling a screen to tubing for running into a wellbore;
providing said screen from materials that enhance buoyancy as
compared to steel construction;
using said buoyancy to enhance advancement of said screen
downhole;
advancing the screen downhole.
15. The method of claim 14, further comprising:
providing portions of said screen in nonmetal materials.
16. The method of claim 15, further comprising:
providing the entirety of said screen in nonmetal materials.
17. The method of claim 15, further comprising:
providing a portion of said screen in composite materials.
18. The method of claim 15, further comprising:
providing a perforated base pipe, a coarse screen and a fine screen
as said screen;
providing one or more of said base pipe, coarse screen and fine
screen in a nonmetal material.
19. A The method of claim 18, further comprising:
providing at least one of said base pipe, coarse screen and fine
screen in fiber epoxy composite material.
Description
FIELD OF THE INVENTION
The field of this invention relates to screen assemblies for
downhole completions, particularly to control production of
sand.
BACKGROUND OF THE INVENTION
In the past, there has been a need to control sand or other solids
produced from the formation with the flowing oil or other
hydrocarbons. Techniques for sand control have involved the use of
screens. Various configurations have been attempted for
sand-control screens. These screens have generally involved a rigid
base pipe which is perforated, overlaid by one or more layers of
screen of different opening sizes. Generally, the finest screen,
which is the one that is designed for catching the sand or other
solid material, is a screen most prone to not only plugging but
also other mechanical ailments.
In the past, these fine filtering screens have used very thin wire
wrapped around the base pipe and an underlying coarser screen. The
filtering screen has generally in the past had a welded
longitudinal seam which failed generally due to erosive effects of
the flow through the screen or chemical attack on the weldment.
Sealing off the ends of the filtering screen to the underlying
support structure has also been problematic. Again, due to the fine
wire size of the filtering screen, welding the ends to a support
body has resulted in failures due to differential expansion
creating tensile loads on welds involving fine wire components of
the filtering screen. Various mechanical efforts to seal the
filtering screen to the underlying structure, such as by use of
mechanical bands, has also failed to provide a tight seal, thereby
allowing the hydrocarbons to short circuit around the filtering
screen, carrying the undesirable sand with them.
In the past, underlying coarse screens below the sand-filtering
screen have been made with a wound wire having a triangular
cross-section, with a flat side oriented outwardly. This has
resulted in coarse screens with fairly small open areas and created
numerous dead spots behind the filtering screen where the flat side
of the triangularly cross-section wound wire of the underlying
coarser screen butted up against the openings of the finer
sand-filtering screen. As a result, the sand-filtering screen
suffered from losses of efficiency due to the numerous dead spots
encountered by the outer flat side of the wound coarse screen
broadly abutting the sand-filtering screen.
U.S. Pat. No. 5,611,399 provides a finished assembly that does not
suffer from welded attachments to thin members, which had in the
past been a weak point in resisting stress, particularly due to
tensile loading, flow erosion, as well as chemical attack. It also
creates an efficient sand-control screen assembly by employing a
substrate of a coarse screen, having wound wires of a more rounded
or arcuate cross-section, to reduce the dead zones in between the
filtering screen and the underlying coarse screen. It also provides
a simple mechanical technique for assembling the elements of the
screen.
U.S. Pat. No. 5,611,399 illustrates a sand-filtering screen-making
technique which involves an initial assembly of the sand-filtering
screen over an underlying coarse screen. The sand-filtering screen
has a mechanical longitudinal fold and overlap-type joint. End caps
are fitted over the filtering screen which has already been
preassembled to the underlying coarse screen. The assembly is then
mechanically forced through a die to compress the end caps into the
assembled filtering screen and underlying coarse screen. That
subassembly is then assembled onto a base pipe and secured. An
outer shroud can then be secured to the underlying base pipe,
overlaying the filtering screen. The ends of the subassembly
comprising the filtering screen and the underlying coarse screen
are sealed against the support pipe by a packing gland arrangement
at both ends.
This design, although an improvement over prior designs, still had
several limitations. Packing glands were required to accommodate
relative movement due to thermal effects. This would present
potentials for leakage at seals. The crimping assembly, involving
overlapping of the ends and folding them over, created a thick
longitudinal seam which tended to decrease the given inside
diameter for a given outside diameter. The annular gap in such a
design, between the outer protective jacket and the filtering
components, also limited the differential pressures that could be
withstood across this screen.
Thus, some of the objectives of the present invention are to
provide a design that could withstand greater differential
pressures than prior designs. Another objective is to be able to
form the assembly so that the fold overlapping of the prior art can
be eliminated, thus enabling the use of a larger inside diameter
for a given outside diameter. Another objective is to eliminate the
floating end rings used in the prior art and secure the filter
directly to a supporting base pipe. Yet another objective is to
provide a technique which will allow low-cost manufacturing of the
filter assembly. Another objective is to be able to hold the filter
media in place with the outer jacket that is pushed on to it in the
extrusion process. Another objective is to provide for an assembly
that allows for use of nonmetallic components such that in long
laterals, the assembly will actually induce buoyancy (cause less
drag/friction during installation) to allow it to be more easily
advanced into position for subsequent production. These and other
advantages will be more apparent to those skilled in the art from a
review of the preferred embodiment described below.
SUMMARY OF THE INVENTION
A method and apparatus for manufacturing any given length of a
completion filter assembly is described. An outer perforated jacket
is assembled over the filter media, which is itself placed over a
coarse support screen or drainage layer. In the preferred
embodiment, the drainage layer and outer jacket have end rings such
that when advanced through a die are pushed together with the
filter media in between to effect a seal of the subassembly. The
subassembly can then be placed on a support pipe which is
perforated, and if metallic, the end rings are welded to the
support pipe to complete the assembly. Optionally, many of the
components can be made of materials which lend buoyancy to the
assembly so that when it is advanced into a long lateral, it will
cause less drag or friction to assist in its proper
positioning.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows in sectional cross-section the subassembly prior to
advancement through a die.
FIG. 2 shows the subassembly after having been advanced through the
die and a base pipe inserted and welded thereto.
FIG. 3 is a sectional along lines 3--3 of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment is illustrated in FIG. 1. An outer shroud
10 has an end ring 12. It has a similar end ring on the other end,
which is not shown. The structure of the outer shroud 10 is a
tubular perforated member whose preferred construction is
illustrated in U.S. Pat. No. 5,849,188 as a jacket 16. Referring to
FIGS. 5a and 5b of that patent, which is incorporated here as if
fully set forth, the jacket can be formed by a spiral pattern of
punched in protrusions 14 which define opposing flowpaths from the
outer surface 16 through openings such as 18 in order to reach the
next layer, which is the filter material 20. The preferred
structure of the filter material 20 is also illustrated in U.S.
Pat. No. 5,849,188 as item 14. Below the filter material 20 is a
coarse filter 22 which is essentially formed of an elongated
material 24 which can have a variety of cross-sectional shapes,
spirally wound so as to create a continuing spiral gap between each
winding as the windings are supported on longitudinally oriented
support rods 26. The coarse filter may also be woven to create said
gap. The end of the structure can optionally contain a solid ring
28. The filter material 20 is rolled into a tubular shape and the
ends are minimally overlapped on each other. One of the ends, shown
in FIG. 1 as item 30, winds up being between ring 28 and ring 12 on
outer shroud 10.
The coarse filter 22, which is preferred, is also illustrated in
U.S. Pat. No. 5,849,188. While the specific design of the three
components shown in FIG. 1 can be preferably made as illustrated in
U.S. Pat. No. 5,849,188, other constructions for the three layers
are within the purview of the invention. For specific applications,
different combinations of two of the three layers previously
described can be used. For example, the innermost coarse filter 22
can be eliminated. The filter material 20 in some applications can
be eliminated. The outer shroud 10 can also be eliminated.
Referring again to FIG. 1, it can be seen that the assembly is
forced through a die 32 which effectively seals the end 30 of the
filter material 20 as it is physically compressed between rings 12
and 28. The outer shroud 10 is plastically deformed by the die 32
such that its inwardly directed protrusions 14 are brought into
contact with the filter material 20. This contact helps to
stabilize the filter material, while the passage through the die 32
seals the subassembly at either end. The entire subassembly shown
in FIG. 1 is shown in FIG. 2 with a base pipe 34 extended through
it. The base pipe 34 has threaded or other well-known connections
37 at either end, and the subassembly 36 is continuously welded or
otherwise joined as indicated at 38. The subassembly of at least
two components can also be secured to the base pipe by passing the
base pipe through the die with it. The base pipe 34 has a series of
openings 40 to complete the filter assembly.
FIG. 3 indicates a section through the completed assembly, showing
the base pipe 34 with its openings 40. Outside of that are the rods
26 which support the spiral windings of the elongated material 24
to form the coarse filter 22. Outside of that is the filter
material 20. Centerline 42, in conjunction with dashed line 44, is
intended to graphically show the amount of overlap between the ends
of the filter material 20. The overlap is preferably kept to a
minimum such as approximately 10.degree. or less which may separate
the centerline 42 from the dashed line 44, representing the degree
of overlap. The amount of overlap-is sufficient to eliminate the
possibility of seam leakage. When the outer shroud 10 is pressed
onto the filter material 20 as a result of advancing it through die
32, the overlapping portion between centerline 42 and dashed line
44 are firmly held together against the support of the coarse
filter 22.
The advantages of this design should now be readily apparent to
those skilled in the art. The close-fit nature of the components,
particularly the outer shroud 10 and the filter material 20, allows
the assembly to withstand significantly greater differential
pressure than the constructions of prior designs, such as that
illustrated in U.S. Pat. No. 5,611,399. Differentials in the order
of 2000 psi could now be used, whereas with prior designs, the
maximum desirable differential pressures were in the order of 600
psi. The need for allowances for differential expansion at the ends
of the filter assembly, as illustrated in U.S. Pat. No. 5,611,399,
is eliminated. The subassembly 36 is directly secured and sealed to
the base pipe 34. Because of the way it is made as described above,
differential expansion is no longer a significant issue.
Those skilled in the art can appreciate that with the assembly
shown in FIG. 1, the filter material 20 is not structural and thus
can be made of a variety of different materials, including
plastics, various fabrics or composite materials. The selected
material for the filter material 20 needs to be capable of
remaining structurally intact, despite advancement of the assembly
36 through the die 32. Similarly, other components of the assembly
36 can be made of nonmetals so as to render the assembly 36 more
buoyant. The scope of the invention encompasses any downhole filter
assembly made with components that make it buoyant or more buoyant.
When the assembly is inserted into a lengthy lateral, its
heightened buoyancy can be a significant aid in advancing the
assembly 36 to the appropriate position. Clearly, the choice of
materials will affect the available differential pressures that the
assembly 36 can withstand. Another alternative is to use buoyant
materials for the base pipe 34 to accomplish this purpose. The
subassembly 36 would then be secured to the base pipe 34 by
techniques such as adhesives or other joining compounds which are
compatible with the temperatures, pressures and chemicals of the
specific application. Thus, for example, the base pipe can be made
of glass fiber epoxy composites such as anhydride or aromatic
amine-cured epoxy pipe or SDT downhole tubing made by Smith
Fiberglass Products Inc. Other types of fiber or polymer matrix can
be used to get the requisite strength and abrasion properties in
combination with a low density. Some examples are polyphenylene
sulfide, polyketones such as PEK or PEEK, epoxy vinyl ester,
phenolic resins, bisphenol, A,fumerate, or isophthalic polyester
resins. These materials can be combined with carbon fiber,
polyester fiber, aramid fiber, glass fiber or other manmade or
naturally occurring fiber.
The method of assembly, as illustrated in FIG. 1, further ensures
that the filter material 20 is uniformly stressed. The assembly
shown in FIG. 2 is sufficiently structurally strong to permit well
killing against the screen. As a result of pulling the assembly 36
through the die 32, the filter material acts in a spring-like
manner against the outer shroud 10. Alternatively, the coarse
filter 22, after pulling through the die 32, can impart spring-like
forces to the filter media 20 against the outer shroud 10. The
filter material 20 can be a simple mesh or a twill or a porous
material and can be made of any one of many materials compatible
with well conditions and the mechanical stresses of the
application. Buoyant materials can also be used.
Those skilled in the art will appreciate that apart from the
technique illustrated in FIGS. 1 and 2, a filter assembly can be
constructed with sufficiently low density due to the use of
composites or other low-density materials so as to allow a filter
assembly, regardless of how it is constructed to be more easily
inserted into a lengthy lateral due to the buoyancy effect. Thus, a
filter material can be attached to a base pipe 34 with or without a
shroud such as 10, as one potential assembly that can be used for
installation and laterals to take advantage of the buoyant
characteristics. Additionally, a low-density material can be used
for the outer shroud 10 and it can have openings of various shapes
and sizes created by a variety of techniques.
The foregoing disclosure and description of the invention are
illustrative and explanatory thereof, and various changes in the
size, shape and materials, as well as in the details of the
illustrated construction, may be made without departing from the
spirit of the invention.
* * * * *